SML Status Report

Don Park donpark at
Sat Jan 8 20:45:25 GMT 2000

Quite a few people have been asking me about the status
of SML.  This is a status report on the SML effort and
the group behind it, the SML-DEV.

So far, we achieved tentative concensus on following

  SML is a strict subset of XML    
  SML supports:
    UTF-8 and UTF-16 only.    
    empty elements.    
    numeric character entities.
    predefined character entities.
  SML does not support:
    CDATA sections
    XML and text declarations
    Processing Instructions
    Entities (except character entities)
  SML attribute names must not conflict with
    child element names.

We are currently trying to formulate an information
model for SML before moving forward to tackle tougher
issues such as attribute, mixed content, and namespace
support.  I think SML represents an unique opportunity
to do things right in the right order.  In contrast,
XML information model is still being worked on, two
years after XML syntax.

There have been some wildly innovative ideas that came
up in SML information model threads: attributed grammars,
colored nodes, rhythmic encoding, unisyntax data model,
and even some Grove model variations.  Beauty of some of
these ideas can be appreciated immediately.  For example,
following is a rather concise notation for our version of
the Groves model:

  node := character | map(string,list(node))

other versions that followed removes the distinction
between a character and a map, and then adds context:

  node = map(string, list(node))
  node = tuple(parent, map(string, list(node)))

Some ideas were less apparent but fantastic nonetheless.
For example, the 'colored node' proposal starts with SML
having just black and white  nodes (name and value),
then treats CSML (Colored-SML), CXML (Common-XML), XML,
XHTML, and arbitrary markup languages as SML with nodes
colored differently (i.e. attribute, PI, comment, etc.).
'colors' differ from 'types' in that the colors are
not 'in' the model but provided by other means such
as parsers or 'painters'.  Leigh Dodds prepared an example
titled "SML Color Book" which shows how the 'painting' is

While these ideas might seem a bit 'off-the-ground' to you,
most members of SML-DEV are as practical as they come, and
plan to use SML and related technologies to build commercial
products.  E-commerce, B2B or B2C data exchange in particular,
seems to be the most common application SML-DEV members are
interested in using SML in.  Just as the design of XML was
influenced by the primary interests of its inventors,
publishing documents on the web, SML's design will likely be
heavily influenced by our interests in e-commerce and data
exchange.  After all, SML will be our child.


Don Park    -   mailto:donpark at
Docuverse   -

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